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Biomedical subjects

M Fukunaga

Publications and source records attributed to M Fukunaga.

At least 217 records · Page 12Linked to original sources
PubMed1995

Genetic and phenotypic analysis of Borrelia miyamotoi sp. nov., isolated from the ixodid tick Ixodes persulcatus, the vector for Lyme disease in Japan.

The ixodid tick Ixodes persulcatus is the most important vector of Lyme disease in Japan. Most spirochete isolates obtained from I. persulcatus ticks have been classified as Borrelia burgdorferi sensu lato because of their genetic, biological, and immunological characteristics. However, we found that a small number of isolates obtained from I. persulcatus contained a smaller 38-kDa endoflagellar protein and single 23S-5S rRNA gene unit. Representative isolate HT31T (T = type strain) had the same 23S rRNA gene physical map as Borrelia turicatae. The DNA base composition of strain HT31T was 28.6 mol% G+C. DNA-DNA hybridization experiments revealed that strain HT31T exhibited moderate levels of DNA relatedness (24 to 51%) with Borrelia hermsii, B. turicatae, Borrelia parkeri, and Borrelia coriaceae. However, the levels of DNA reassociation with the previously described Lyme disease borreliae (B. burgdorferi, Borrelia garinii, and Borrelia afzelii) were only 8 to 13%. None of the previously described species examined exhibited a high level of DNA relatedness with strain HT31T. In addition, the 16S rRNA gene sequence (length, 1,368 nucleotides) of strain HT31T was determined and aligned with the 16S rRNA sequences of other Borrelia species. Distance matrix analyses were performed, and a phylogenetic tree was constructed. The results showed that isolate HT31T is only distantly related to both previously described Lyme disease borreliae and relapsing fever borreliae. Thus, the spirochetes isolated from I. persulcatus and closely related isolates should be classified as members of a new Borrelia species. We propose the name Borrelia miyamotoi sp. nov. for this spirochete; strain HT31 is the type strain.

Animals↗
PubMed1995

Endovascular papillary angioendothelioma-like tumour associated with lymphoedema.

A case of endovascular papillary angioendothelioma-like tumour associated with lymphoedema is described. Microscopically, the tumour was composed of anastomosing vascular channels, some of which contained papillary projections, producing tuft-like or glomeruloid appearances. The dermis also showed moderate lymphoedema and lymphocytic infiltrate. The tumour resembled endovascular papillary angioendothelioma but also had several features that differed from typical examples: occurrence in an old patient and less prominent endothelial hobnail features and lymphocytic infiltrate. Three types of proliferating cells were observed: 1 mature flattened endothelial cells, which were strongly positive for endothelial markers (factor VIII-related antigen, CD31, CD34) and bound ulex europaeus agglutinin 1;2 immature endothelial cells with round nuclei and vacuolated or pale cytoplasm, which were strongly positive for CD31 and muscle-specific actin (HHF35) and focally positive for other endothelial markers; and 3 stromal spindle cells in papillary or glomeruloid areas, which were positive for vimentin, HHF35, and alpha-smooth muscle actin but negative for desmin. The tumour was diploid by flow cytometry. The patient was well without disease twelve months after the excision. We postulate that this tumour was caused by circulatory disturbance, namely lymphoedema associated with syringomyelia and a Charcot's joint.

Aged↗
PubMed1995

Atypical polypoid adenomyomas of the uterus.

We performed a clinicopathological immunohistochemical, ultrastructural, and flow cytometric study on six cases of atypical polypoid adenomyoma of the uterus including one with an adenocarcinoma within it. The tumours occurred in nulliparous women aged 22-48 years (average, 33.0 years); three arose in the uterine corpus, and three in the endocervix. Histologically, they were composed of endometrial glands admixed with a stromal component of interlacing bundles of smooth muscle cells. The glands exhibited varying degrees of architectural and cytological atypia. Most of the stromal cells showed strong staining for HHF35, alpha-smooth muscle actin, and vimentin, and some cells contained desmin. Electronmicroscopy, in one case, confirmed the presence of a well-differentiated smooth muscle component. The stromal component may arise as a result of extensive metaplasia of endometrial stromal cells. Uninvolved endometrium showed ciliated cell metaplasia in three patients, and atypical complex hyperplasia in two. One patient had a well-differentiated adenocarcinoma of endometrioid type arising in an endocervical atypical polypoid adenomyoma. All tumours had a diploid DNA content and relatively small S phase fraction (average, 6.23%). The follow-up periods ranged from 4 to 42 months (average, 13.5 months), and all patients were alive and well. Although the histogenesis of atypical polypoid adenomyoma of the uterus remains uncertain, it is suggested that it may arise because of oestrogen-related factors.

Adenomyoma↗
PubMed1995

Choriocarcinoma in situ: a case at an early gestational stage.

A case of choriocarcinoma in situ arising in an 11 week gestational placenta is reported. Histologically, a localized nodule, measuring 5 mm, of neoplastic trophoblastic proliferation appeared to arise directly from normal stem villi and projected into the intervillous space. The tumour was composed of biphasic cytotrophoblast and syncytiotrophoblast. No fetal elements were observed. The patient had a normal full-term spontaneous vaginal delivery 22 months after curettage and was free of disease without therapy at 32 months. This tumour provides evidence for an origin of choriocarcinoma from villous trophoblast. Our report illustrates the need to perform thorough microscopic examination of the products of conception, especially in the absence of a fetus or fetal parts.

Adult↗
PubMed1995

Yolk sac tumour of the ear.

We report the second known case of yolk sac tumour of the external auditory canal, occurring in an eight-month-old girl. The excised tumour demonstrated histopathological and immunohistochemical features identical to those of yolk sac tumours of gonadal origin. The tumour was aneuploid by flow cytometry. The patient received chemotherapy post-operatively and has had no evidence of disease 13 months after surgery.

Ear Canal↗
PubMed1995

Solitary fibrous tumor of the nasal cavity and orbit.

Solitary fibrous tumors (SFT) are rare spindle cell neoplasms generally associated with the serosal surface, especially the pleura. Two SFT are reported arising in the nasal cavity and orbit, occurring in a 33 year old female and a 21 year old male, respectively. The lesions lacked the characteristic features of other recognized neoplasms that occur in these regions. Immunohistochemically, the tumors cells were diffusely and strongly positive for vimentin and CD34 and some or many tumor cells expressed neuron-specific enolase and Leu-7. Ultrastructurally, the tumor cells showed no distinct features although they were suggested to be primitive mesenchymal or fibroblast-like cells. Both tumors were diploid by flow cytometry. The two patients have had benign clinical courses with limited follow-up. Our findings suggest that SFT is of mesenchymal cell origin and support another location for SFT, indicating additional evidence against mesothelial origin. SFT should be included in the differential diagnosis of spindle cell tumors arising in the nasal cavity and orbit.

Adult↗
PubMed1995

Immunohistochemical and flow cytometric study of neuroendocrine carcinoma of the skin.

Immunohistochemical and flow cytometric analysis using formalin-fixed, paraffin-embedded sections was performed on 10 neuroendocrine carcinomas of the skin (NCS). Grimelius staining was positive in seven tumors. All tumors showed coexpression of CAM 5.2 and neuron-specific enolase with paranuclear dot-like or diffuse cytoplasmic reactivity. Neurofilament was positive in five cases, chromogranin in six, calcitonin and carcinoembryonic antigen in two each, and somatostatin and S-100 protein in one each. Eight primary lesions were diploid and the remaining two were aneuploid; however, two diploid NCS presented as aneuploid metastatic tumors. The follow-up periods ranged from 3 to 66 months (mean 13.6). Six patients died of metastatic diseases between 3 and 33 months (mean 9.2) after the diagnosis. There were no significant correlations among histologic features, DNA ploidy, S-phase fraction, and clinical outcome of the patients with NCS. These results indicate that a panel of antibodies may be required for immunohistochemical confirmation of neuroendocrine differentiation and that a flow cytometric analysis is not a good tool to predict the biologic behavior of NCS.

Aged↗
PubMed1995

Spindle cell hemangioendothelioma: an immunohistochemical and flow cytometric study of six cases.

Six cases of spindle cell hemangioendothelioma (SCH) are presented with immunohistochemical and flow cytometric analyses. One case was associated with Maffucci's syndrome. All lesions were solitary or multifocal in the extremities, and prepresentation duration ranged from years to decades. One case recurred but none had metastases. Histologically, in four of the six cases the main lesions appeared to arise within vessels, predominantly muscular vessels. All lesions consisted of cavernous hemangioma-like areas and solid cellular areas resembling Kaposi's sarcoma. Cellular atypia was minimal. At the periphery of the lesions, a cluster of large thick or thin walled, and probably malformed, vessels were observed. Immunohistochemically, factor-VIII related antigen, CD34, vimentin, and lectin binding Ulex europaeus agglutinin 1 stained endothelial cells lining vascular channels, and vacuolated, or epithelioid cells. Spindle cells in the solid areas were negative for these endothelial markers except for vimentin, but showed divergent positive immunoreactions of HHF35, alpha-smooth muscle actin, desmin, and collagen type IV. Five cases were diploid and one was aneuploid. There was no significant correlation among DNA ploidy, S-phase fraction, and local recurrence in SCH although the number of cases examined was small. These results suggest SCH may be a benign lesion, probably a reactive process, rather than a low-grade angiosarcoma.

Adult↗
PubMed1995

Outer surface protein C gene sequence analysis of Borrelia burgdorferi sensu lato isolates from Japan.

The nucleotide sequences of the outer surface protein C gene (ospC) from Borrelia burgdorferi sensu lato isolates representing six different restriction fragment length polymorphism (RFLP) ribotype groups were determined, and the deduced amino acid sequences were aligned in comparison with the previously published OspC protein sequences. The sequence similarity analysis revealed the high sequence variability of OspC protein, and the degree of amino acid similarity ranged from 53.8 to 100% among 25 isolates. It has been reported that the representatives belonging to the three species of B. burgdorferi sensu lato showed a species-specific amino acid sequence motif at positions 23 to 35 (B. Wilske, S. Jauris-Heipke, R. Lobentanzer, I. Pradel, V. Preac-Mursic, D. Rössler, E. Soutschek, and R.C. Johnson, J. Clin. Microbiol. 33:103-109, 1995). Alignment with the OspC sequences of RFLP ribotype group IV, V, and VI isolates revealed that a sequence motif of all the isolates was quite similar to that of Borrelia garinii. A phylogenetic analysis based on OspC protein sequences also showed that most of the Japanese isolates were closely related to the species B. garinii. THe RFLP ribotype group IV species is predominant among clinical isolates of Lyme disease patients, reservoir rodents, and adult ticks in Japan. Although the isolates differed from type strains of the three delineated genospecies in genetic and immunological characteristics, it is likely that the spirochetes diverged within the species level. Therefore, the representatives of ribotype groups IV, V, and VI appear to have evolved within B. garinii and to have adapted to an Asiatic habitat, and there appeared to be a sufficient ecological pressure to allow bacterial species level development.

Amino Acid Sequence↗
PubMed1995

Non-invasive measurement of brain activity using functional MRI: toward the study of brain response to acupuncture stimulation.

We studied functional MRI in 15 male and 13 female normal volunteers on a clinical MRI system using gradient echo sequence. During the experiments, brain activation was induced by grasping the unilateral hand once or twice a second for motor tasks. A localized increase of MRI signal in the contralateral motor cortex was observed in 17 out of 21 cases (81%) under right hand motor task and 11 out of 21 cases (52%) under left hand motor task. The application of this method may be useful to evaluate brain response to acupuncture.

Acupuncture Therapy↗
PubMed1995

Role for Doppler ultrasound in the assessment of renal circulation: effects of dopamine and dobutamine on renal hemodynamics in humans.

To examine the utility of Doppler ultrasound in assessing renal hemodynamics, we investigated the effects of dopamine and dobutamine on renal blood flow using Doppler ultrasound technique and conventional clearance tests in 7 healthy volunteers. After visualization of arterial blood flow in the right renal hilus by two-dimensional color flow mapping, the phasic blood flow velocity in the vessel was obtained by a pulsed Doppler method. Intravenous infusion of dopamine at a low dose increased the velocity and decreased the waveform pulsatility of renal artery blood flow without causing any significant changes in blood pressure, heart rate, or cardiac index. In contrast, dobutamine infusion increased the peak systolic velocity in a dose-dependent manner, but did not increase the mean velocity or decrease the waveform pulsatility. Percent changes of renal blood flow during infusions of both agents correlated well with those of the mean velocity. Furthermore, the degrees of changes of the waveform pulsatility were consistent with those of renal vascular resistance obtained from clearance tests and blood pressure. Our results suggest that mean velocity reflects renal blood flow and the pulsatility of blood flow waveform represents renal vascular resistance. We conclude that the effects of vasoactive agents on renal blood flow and renal vascular resistance can be estimated noninvasively, directly, and repeatedly using Doppler ultrasound.

Adult↗
PubMed1995

Immunohistochemical study of gamma delta T cells in human gingival tissues.

The distribution and the density of gamma delta T cells in human gingival tissues were examined immunohistochemically in biopsy samples obtained from 20 subjects. Few gamma delta T cells were observed in gingival tissue free from inflammatory cell infiltration, but were found, albeit in low numbers, in association with inflammatory cell infiltration, especially T cells. This relationship with T cells was confirmed statistically. The ratios of gamma delta T cells to T cells in the epithelia and in the connective tissue were calculated in the sections in which more than 500 CD3-positive cells were identified. Seven of eight such epithelial specimens showed a ratio of less than 1% and one less than 2% (mean +/- SD; 0.8% +/- 0.4). In the connective tissue, 8 of 13 such specimens showed less than 1%, three less than 2%, one 3%, and one 7% (1.4% +/- 1.9). These results suggest that basically gamma delta T cells are not resident cells in the gingival epithelium such as comprise the first defense line against exogenous irritation. They may play some role in the pathogenesis of periodontal disease collaborating with alpha beta T cells in the inflammatory response.

Adult↗
PubMed1995

A small dose of human parathyroid hormone(1-34) increased bone mass in the lumbar vertebrae in patients with senile osteoporosis.

Intermittent treatment with human parathyroid hormone (hPTH) has been shown to increase cancellous bone mineral density (BMD) in osteoporosis, but its effects on cortical bone remain controversial. In this study, the effects of hPTH(1-34) administered at a dose of 6 micrograms (20 units) per day subcutaneously for 26 weeks were investigated in 16 patients with senile osteoporosis. The changes in BMD in lumbar vertebrae were measured using dual energy x-ray absorptiometry. BMD in the second metacarpal bone was simultaneously measured with radiogrammetry to find changes in BMD in cortical bone. Serum and urinary biochemical parameters were also evaluated. The lumbar BMD increased significantly at the end of the treatment without decrease in the cortical bone mass. Biochemical markers of bone formation were also elevated, while markers of bone resorption did not show striking changes during the treatment. In conclusion, daily administration of low doses of hPTH(1-34) stimulated bone formation and increased bone mass in patients with senile osteoporosis without combination with another therapeutic agent.

Aged↗
PubMed1995

[Detection and localization of enlarged parathyroid glands in patients with hyperparathyroidism using 99mTc-methoxyisobutylisonitrile (MIBI): a study of subtraction scintigraphy with 99mTc-pertechnetate].

In this study we investigated the detectability of abnormal parathyroid gland(s) by 99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy in patients with hyperparathyroidism. The subjects were 6 patients with primary hyperparathyroidism (PHP) with a single adenoma and 13 patients with renal hyperparathyroidism (RHP) on chronic maintenance hemodialysis. The imaging data of 99mTc-pertechnetate were subtracted from those of 99mTc-MIBI (MIBI-Tc), and number and location of the positive images on scintigrams were compared with those obtained by conventional scintigraphy using 201Tl-Cl and 99mTc-pertechnetate (Tl-Tc). All of the patients underwent surgery, and the number and location of the abnormal parathyroid glands were confirmed. The number of resected parathyroid glands were 6 in PHP and 52 in RHP. The detectability of MIBI-Tc was 83.3% in PHP and 51.9% in RHP, while that of Tl-Tc was 100% and 44.2%, respectively. Although no statistically significant difference in the detectability was found between MIBI-Tc and Tl-Tc, the number of false positives with MIBI-Tc was less than that with Tl-Tc. The detectability of MIBI-Tc depended on the size of the parathyroid gland. The maximal diameter and weight of the smallest parathyroid gland detected were 15 mm and 290 mg in PHP, and 9 mm and 50 mg in RHP. The existence of the thyroid gland did not reduce the detectability of MIBI-Tc. In conclusion, MIBI-Tc was clinically very useful for the detection of abnormal parathyroid glands in patients with hyperparathyroidism.

Adult↗
PubMed1995

[Serial 123I-IMP SPECT in a case of cryptococcal meningoencephalitis].

We performed serial brain perfusion SPECT studies using 123I-IMP in the course of cryptococcal meningoencephalitis. Increased perfusion was detected in the cerebellum coinciding with the appearance of the abnormality on MRI. The perfusion in the lesion was then decreased as the abnormality on MRI disappeared. Cryptococcal meningoencephalitis should be also taken in the differential diagnosis when the inflammatory brain lesion shows increased perfusion.

Aged↗
PubMed1995

[Study on tumor accumulation property of 99mTc-HM-PAO and 99mTc-MIBI in rabbits bearing VX-2 cancer].

Each of blood flow imaging agents has a potential usefulness as an agent for tumor scintigraphy. The usefulness for tumor scintigraphy of two agents, i.e. cerebral blood flow scintigraphy agent 99mTc-HM-PAO and myocardial blood flow scintigraphy agent 99mTc-MIBI, was comparatively studied using rabbits bearing VX-2 cancer. From then to twenty days after the implantation of VX-2 cancer into the femoral region of five rabbits, tumor to soft tissue accumulation ratio (T/S ratio) of each agent was calculated in early images (5 min after injection) and in late images (50 min after injection). Compared with 99mTc-MIBI, the T/S ratio of 99mTc-HM-PAO was higher and, moreover, the washout was delayed. These results suggest that there is a difference in tumor accumulation property between these two agents.

Animals↗